Humidity and antifreeze

My Duster leaks a small amount of antifreeze. I drove it last night and it had been sitting for one week. When I pulled it out I viewed what had leaked it was a milky substance. If I look beneath the car after a couple days of sitting I can see the green drops on the floor obviously being antifreeze. All of last week was extremely humid and lots of rain towards the end of the week. Outside was very muggy and misty. My question is would the humidity make the antifreeze expand and turn it almost white? My garage is a pool barn type of building apart from the house so it's just as hot if not hotter in there than outside. I just thought it was strange. The humid weatehr is the only thing I can think and anti-freeze is all the car has been leaking latley.

Any information is greatly appreciated. Thanks